1. Field of the Invention
The present invention relates optical communications systems and to a latching apparatus for a pluggable optical transceiver module.
2. Description of the Related Art
With the development of information and communication technologies, optical communication systems by which bulk information can be transmitted at a high data rate with a few communication lines have been popularly used to transmit more information using limited lines in various communication networks and intelligent networks.
In the optical communication systems, optical communication devices, such as optical communication switches, which have been developed on the basis of various standards, and optical transceiver modules such as a gigabit interface converter (GBIC), are used to convert input optical signals to electrical signals and electrical signals to output optical signals.
Each optical transceiver module includes an optical connecting device containing a light source, a light source detector, an optical transmission circuit, and an optical reception circuit.
The optical transceiver modules are produced on the basis of various standards in which module specifications are propagated to miniaturize optical communication electronic devices.
For example, the 10 Gigabit Small Form Factor Pluggable (SFP) Multi-Source Agreement (MSA) Revision 3.1, is a standard propagated for a small form factor optical transceiver module.
FIGS. 1 through 6 illustrate structural elements of an SFP module 10. Functions of main elements will now be schematically described.
Referring to FIGS. 1 and 2, the SFP module 10 is a pluggable optical transceiver module including electrical connector 15, which is an electrical contact point between a host board 20 and the SFP module 10. Cage assembly 21 is a housing assembled to fix the SFP module 10 including the electrical connector 15 thereto. Heat sink 22 radiates heat generated by the SFP module 10 to the outside environment, and clip 23 fixes the heat sink 22 to the cage assembly 21.
The SFP module 10 and the cage assembly 21 will now be described with reference to FIGS. 1 through 6.
Referring to FIGS. 1 through 3, the SFP module 10 includes insertion holes 13 for inserting an optical connector 40 (see FIGS. 12 and 16) thereinto, a latch 30, and a locking arm 31. When the SFP module 10 is plugged in or unplugged from the cage assembly 21, the locking arm 31 (FIG. 2) is locked in or unlocked from a locking catch 21c (FIG. 3) included in the cage assembly 21 by pushing the latch 30.
Referring to FIGS. 4 and 5, when it is intended to unplug the SFP module 10 from the cage assembly 21, by pushing the latch 30 an end of the latch 30 guides and lifts up an end of the locking catch 21c, and then the SFP module 10 is pulled when the locking arm 31 is unlocked from the locking catch 21c. 
Thus, the SFP module 10 is unplugged from the cage assembly 21 as shown in FIG. 6.
When it is intended to plug the SFP module 10 in the cage assembly 21, which is performed by pushing the latch 30 into the cage assembly 21, the locking arm 31 is guided by the end of the locking catch 21c and bends and lifts up the end of the locking catch 21c. The SFP module 10 is then fixed to the cage assembly 21 by the insertion of locking arm 31 into the locking catch 21c. 
The pluggable optical transceiver module 10 is unplugged from the cage assembly 21 by lifting up the locking catch 21c by pushing the latch 30 and pulling the pluggable optical transceiver module 10 while maintaining a state of pushing the latch 30.
As described above, since a conventional pluggable optical transceiver module is unplugged from a cage assembly by pulling the conventional pluggable optical transceiver module while maintaining a state of pushing on a latch, it is difficult for the conventional pluggable optical transceiver module to be unplugged from the cage assembly. Therefore, whenever the conventional pluggable optical transceiver module is unplugged from the cage assembly for test or maintenance activities, user inconvenience is caused by repeating the process described above.
Hence, there is a need in the industry for a means for unplugging an optical module without the inconvenience caused by having to push on the module to unattached it from the locking mechanism.